Sewing-machine



J. KIEWICZ.

SEWING MACHINE.

APPLICATION FILED JAN-2.1919.

Patented Dec. 14, 1920.

3 SHEETS-SHEET 1.

firm/7X0 John K iewicz.

J. KIEWICZ.

SEWING MACHINE.

'APPLICATION FILED mm. 1919.

1,361,871, Patented Dec. 14, 192( v a SHEETS-SHEET 2.

John Kiewicz. 4 m 21m J. KIEWICZ.

SEWING MACHINE.

APPUCATION FILED JAN.2, 19w;

1,361 ,871 Patented Dec. 14, 1920.

3 SHEETSSHEET 3- I/fl MM? John Kiewicz UNITED STATES PATENT OFFICE.

JOHN KIEWICZ, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REECE BUTTONHOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

SEWING-MACHINE.

Specification of Letters Patent.

Patented Dec. 14, 1920.

Application filed January 2, 1919. Serial No. 269,201.

To all whom it may concern: Be it known that I, J OHN Kinwicz, a(Hillzen of the United States, residing at Boston,

county of Suffolk, State of Massachusetts, have invented an Improvementin Sewing- Machines, of which the following description, in connectionwith the accompanying drawin is a s ecification. like characters IVherethe under thread is thus cut close to the work at the end of thestitching on a luittonhole, it is desirable that a suflicient length ofunder thread should be left pro truding' from the under thread mechanismthat when the stitching is started again on another buttonhole the firststitch will be properly formed because if the thread end is too short,there is danger that it will be pulled through the work in tighteningthe first stitchjthus making an imperfect stitch.

It'is one of the objects of my present invention to provide a novelthread-pullingofi device which becomes operative automatically when thestitching on any buttonhole is completed to draw off from the source ofsupply a length of under thread before the thread is cut so that therewill be left protruding from the under thread mechanism the requiredlength to insure the correct formation of the first stitch.

Another object of my invention is to provide a novelthread-pulling-oiidevice which is arranged to be actuated by theactuator that controls the thread-trimming mechanism so that oneactuator is sufficient to operate both the thread trimmer and thethread-pulling-ofi device.

Other objects of my invention are to imorove generally threae trimmingand thread-pulling-ofl' devices for buttonhole sewing machines, all aswill be hereinafter set forth. n

In order to give an understanding of my iuventioiu I have illustrated inthe drawings a selected embodiment thereof which will now be described,after which the novel features will be pointed out in the appendedclaims.

In the drawings, Figure 1 is a side view of a buttonhole sewing machineembodying my invention;

Fig. 2 is a plan view of a part of the base frame with the clampsremoved for the purpose of showing better the construction and operationof the pull-off device for the under thread;

Fig. 3 is an underside view of the bed plate showing theractuator forthepull-off and thread-trimming devices;

Figs. 4 and 5 are plan views of the clamp plate showing the operation ofthe thread trimmer and the pull-off device.

Since my invention relates particularly to the means for pulling off theunder thread and for cutting or trimming the thread. I have not deemedit necessary to illustrate herein a complete buttonhole sewing machine,but have contented myself with illustrating a suflicient portion of .thesewing machine to enable the invention to be understood.

1 indicates the bed plate of a sewing machine from which rises the heador overhanging arm 2 carrying the upper threadhandling mechanism whichis herein shown in the form of a reciprocating eye-pointed needle 3 thatis carried by the usual reciprocating needle bar l.

The bed plate 1 carries the work-holding means which is herein shown inthe form of the usual clamp plate 5 that is slidably mounted in ways 6formed on the bed plate land work clamps 7 which are pivotally mountedon the clamp plate 5. Situated beneath the bed plate 1 is theunder-threadhandling mechanism which is indicated generally at 8 andwhich maybe of any suitable or usual type. In the type of sewing machineherein shown this under-threadhandling mechanism is carried by a turretwhich is rotatably mounted in suitable bearings carried by the dependingportion 9 of the frame, said turret sustaining at its up- .per end thethroat-plate 10 which is pro vided with an aperture 11 through whichtheunder thread 12 extends and through which the needle 8 passes whensaid needle descends through the work. The under thread mechanismisprovided with the longitudinally of the ways 6 for feeding the workduring the stitching operation and also for the purpose of carrying thework from stitching to buttonhole-cutting -posi-' tion at the end of thestitching operation by means of the usual main cam indicated generallyat 14:, the connections between the clamp plate and the main cam beingsuch. as are ordinarily employed in buttonhole sewing machines of thistype. c

The parts; thus far described may have any suitable construction but forillustrative purposes they are shown as having substantially'the sameconstruction as will be found in United States Letters Patent No.1,188,944, dated June 27, 1916, or in my co-pending application Se. No.203,899, filed November 26, 1917.

Buttonhole sewing machines of this type are usually constructed so-thatwhen they are set in'operation the work clamps 7 are first closed ontothe work to indicated in dotted lines Fig. 1, thereby clamping thelatter to the clamp plate 5, and the buttonhole cutter, if oneis used,is actuated to cut the buttonhole after which the clamp plate is movedtoward the front of the machine to carry the work frombuttonhole-cutting to stitching position. The stitch forming mechanismis then set inoperation and the stitching proceeds down one side of thebuttonhole and back along the other side, the clamp plate 5 being giventhe appropriate feeding movement to feed the work properly. At

the end of the stitching operation on the buttonhole the sewing machineis brought to rest with the needle 3 raised and the work clamps 7 arethen released to unclamp the work, after which the clamp plate is givena move- I ment to carry the work from stitching to buttonholecuttingposition. After this cycle of operations has been completed, the

machine is brought to rest The sewing machine herein illustrated isprovided Wlth tread-trimming mechamsm which s carried by 'the clampplate 5 and operates to cut the under thread close to and mechanismcomes unclamped.

beneath the work when the stitch-forming to rest and the work is Thisthread-trimming device is somewhat I Y similar to that illustrated in myco-pending application, Se. No. 203,899, andeomprlses two thread-cuttingjaws 15 and 16 which are pivotally connected together at 17 and p areslidably mounted on the clamp plate 5.

Each'jaw has an inclined slot formed in its rear end, said slots beingindicated at- 18 and 19, respectively,-said slots receiving a pin 20carried by a lever 21 which is pivoted at 22 to the clamp frame 5. Thethreadcutting jaws are capable of bodily movement toward and from thethroat-plate 10 and are guided in their movement by a swinging arm 24,one end of which is pivotally connected to the pivotal pin 17 and theother end of which is pivoted to the clamp plate at 25. This arm 24plays between two stops 23 and 53 which limit its swinging movement andthereby limits the reciprocating movement of the jaws. 'Thethread-trimming devices are situated on the upper side of the clampplate but occupy a position beneath the work 10 when the work is appliedvices normally-occupy a retracted position shown in Fig. 4: during thestitching operation and are yieldingly held in such position by means ofa spring 26, which-acts on a pin or projection 27 extending from thelever 21. The action of this spring 26 normally holds the pin 20 at theleft-hand ends of the slots 18 and 19, as seen in Fig. at whereby thejaws 15 and 16 are held in their open position. When the cutting jawsare in their retracted position they are situated in front of thethroat-plate or stitching point, as shown in Fig. 4, and hence do notinterfere with the stitching operation. When the stitching on thebuttonhole has been completed and the work-clamps 7 are released,;thelever 21 is -swung toward the throat-plate and during the first part ofthe swinging movement'of the lever, the open jaws 15 and 16 will bemoved bodily toward the'throat-plate until the arm 24 strikes the stop23, at which time the cutting edges 28 of said jaws are situated overthe throatplate 10 so that the under thread and the loop of upper threadthat is retained by the looper will be situated between the cuttingedges. Further swinging movement of the lever 21 will carry the pin 20to the righthand end of the slots 18 and 19, thus closing the cuttingaws and severing both the under threadand the loopof upper thread, asseen in Fig. 5; This form of thread-cutting device is substantially thesame as that illustrated in my co-pendingapplication Se. No.

the main cam 14. This main cam is provided with a hub 37 which dependsthrough the camhousing 38 and to which the arm 36 is secured. The maincam 14 and consequently the arm 36 make one complete revolution for eachbuttonhole, and the parts are so designed and timed that the roll 35will actuate the lever 30 at the point in the cycle of operations whenthe sewing on the buttonhole has beeen completed and just as the workclamps 7 are released. The movement of the actuator 30 operates thelever 21 there by to move the thread-trimming devices into operativeposition and actuate them to trim the thread, as above described.

1 In order to pull off from the source of supply a sufficient length ofunder thread to provide for forming properly the first stitch when thesewing machine is started in operation, I have provided a pull-off lever39 which is pivoted at 40 on the end of the bed plate 1 and beneath theclamp plate This pull-off lever 39 is acted upon by a pulling spring 41which normally holds it in its full line positions Figs. 2 and 4. Theend 42 of the lever is situated close to the throatplate 10 and isprovided with a thread-engaging notch 43 and said lever is so shaped andconstructed that when it is swung from the full to the dotted lineposition, Fig. 2, the end 42 thereof will be carried beneath thethroat-plate 10 and the notch 43 will be brought against the portion ofthe under thread 12 leading from the under thread mechanism up throughthe throat-plate.

During the sewing operation, the pull-off lever 39 is in its retractedor full-line position, Fig. 2, but at the end of the stitching operationand before the thread-trimming device is actuated to cut the thread,said lever is swung from its full to its dotted line position Fig. 2,during which swinging movement the notch 43 engages the under thread 12and draws off a length from the source of supply, it being understood,of course, that the thread is at this time connected to thework.Immediately after this required length of under thread has been pulledfrom the source of supply, the threadtrimming device is actuated, asabove 'described, to cut the under thread.

In order to simplify the mechanism, I have provided a constructionwherein the pulling-off movement of the pull-off lever 39 is effected bythe actuating. lever 30 so that said lever 30 operates both the pullofflever, and the thread-trimming device. For this purpose the pull-offlever 39 is provided with the tail or extension 44 which normallyextends beyond the tail 33 of the lever 21, the end of the extension 44being formed with the cam surface 45 with which the upstanding part 32of the lever 30 normally has engagement. Hence during the initialmovement of the actuating lever 30 the part 32 operates on the camsurface 45 thereby to swing the pull-oft lever 39 from the full to thedotted line position. and pull off the required length of under threadfrom the source of supply. The inner face or edge 47 of the extension 44has such a shape that after the end 32 of the lever 30 has passed thecorner 46, said lever can return toward its normal position under theinfluence of the spring 41 thereby letting up on the under thread. Therelative position of the tail 33 of the lever 21 and the cam surface 45of the extension 44 is such that the end 32 of the lever 30 will engagethe tail 33 immediately after it has passed the corner 46 so that assoon as the under thread has been pulled off and then the pressure ofthe pull-off on the under thread has been released, the thread-trimmingdevice is moved into position to engage the thread and then'is actuatedto sever the thread.

The advanta e derived from thus releasin c; 23

tion, means to produce a relative work-feeding movement between thework-holding means and the frame carrying said stitchforming mechanism,a thread-trimming device carried by the work-holding means and operatingto cut the under thread beneath the work at the completion of the sewingoperation, a pull-off device mounted'on said frame and adapted to pulloff a length of under thread from the source of supply, and

an actuator common to both devices.

2. In a sewing machine, the combination with a frame, ofstitch-forming'mechanism carried by the frame and adapted to concatenatean upper and an under thread, work-holding means constructed to hold thework clamped during the stitching operation, means to produce a relativework-feeding' movement between the work-holding means. and the framecarrying said stitchforming mechanism, a thread-trimming device carriedby the work-holding means anl operating to cut the under thread beneaththe work at the completion of the sewing operation, a pull-off devicemounted on said frame and adapted to pull off a length of under threadfrom the source of supply, and

-an;actuator common to both devices'and arranged first toactuate thepull-offrdevice and then subsequently toloperate the trimming device.

3. In a sewing machine, the combination with stitch-forming mechanismfor c0ncatenating an upper and an under thread, of work-holding means, amain cam for producing a relative feeding movement .between thestitcheforming mechanism and work-holding means,'a thread-trimming doevice carried by the work-holding means, a pull-olf device supportedindependently of the worl-r-holding means and arranged to pull oil" alength of under thread from the source of supply, an actuatorconstructed to actuate first the pull-oif device and then thethreadtrimming device, and means rigid with the main cam for operatingsaid actuator. l a

12. in a sewing machine, thecombination with stitch-forming mechanismfor concatcnating an upper and an under thread, of

work-holding means, a main cam for producing a relative feeding movementbetween the stitch forming mechanism and work holding means, athread-trimming device carried by the work-holding means for cut tingthe under thread beneath the work, a pull-off device supportedindependently of the worlcholding means and arranged to pull ofl alength of under threadfrom' the source of supply, a lever adapted by itsswinging movement to actuate first the pulloil and then thethread-trimming device, and means associated with the main cam foractuating said lever.

In a sewing machine, the combination with work-holding means, ofstitch-forming mechanism for concatenating an upper and an under thread,a main cam for producing a relative feeding movement between thestitch-forming mechanism and work-hold ing means, a pull-elf deviceadapted to pull. oii a length of under thread from the source of supply,a thread-trimming device separate from the pull-off device, apivotallymounted actuating lever adapted during its turningmovementfirst to actuate the pulloil device and then to operate the,trimming device, and means associated with the main cam to operate saidlever.

6. In a sewing machine, the combination '7. In a sewing machine'of thetype 0011- structed to sew a short seam and then come to rest, thecombination :with a frame, of workholding means movably mounted thereon,means to give s'aidwork-holding ried icy-the work-holding means, andmeans common to both devices to actuate them.

, s 8. In a sewing machine of the type constructed to sew a short seamand then to come to rest, the combination with a frame,

of work-holding means, movably mounted thereon, means tc give saidwork-holding means a feeding movement, stitch-forming means constructedto concatenate an upper and an under: thread, a pull-off device ,mountedon the frame and adapted to pull off a length of under thread from tl csource c-f supply, a thread-trimming device for cutting the under threadbeneath the work carried by and movable with the work-holding means, anactuating'lever common toboth devices, and means to actuatevsaid leverat the end of a sewing operation.

9. In a sewing machine, the combination with a frame having a bed plateportion, of worleholding moans, s'lida-bly mounted thereon, astitch-forming mechanism for concatenating an upper and anunder threadand including a throat-plate through which the threads pass, a pull-offdevice mounted on the bed plate to swing in a horizontal plane andadapted by its swinging movement to pull off a length of under thread,

said device having a cam surface, an actuating lever adapted by itsswinging movement to wipe over said cam, surface thereby to actn ate thepull-oil device and then to release the latter, and a spring to returnthe pull-off device to normal position.

it). In a sewingmachine, the combination with a frame having a bed plateportion, of work-holding means slidably mounted thereon, astitch-forming mechanism including a throat-plate through which thethreads pass, a pull-off member pivoted to the bed plate beneath theworkrholdingmeans and adapted to swing in a horizontal plane and by itsswinging movement to pull off a length of under thread, one end of saldmember projecting beyond the end of the bed plate,

and an actuating lever pivoted to the frame and adapted to engage theprojecting end of the pull-off member.

11. In a sewing machine, the combination with a frame having a bed plateportion, of work-holding means slidably mounted thereon, stitch-formingmechanism including a throat plate through which the threads pass, apull-off member pivoted to the bed plate beneath the work-holding .meansand adapted to swing'm a horizontal plane and byits swinging movement topull off a length of under thread,:ione end of said member projectingbeyond the end of the bed plate, a thread-trimming device car- 'ried bythe work-holding means, and an actuating lever pivoted to the frame andadapted by its swinging movement to engage the projecting end of thepull-off lever thereby to actuate the latter and then to actuate thethread-trimming device.

12. In a sewing iachine, the combination with stitch-forming mechanismfor concatenating an upper and an under thread, of work-holding meansfor holding the work clamped during the stitching operation, means toproduce a relative feeding movement between the stitch-forming mechanismand the work-holding means, a thread-trimming device carried by thework-holding means and operating to out the under thread beneath thework at the completion of the stitching operation, a pull-off deviceadapted to pull off a length of under thread from the source of supplyand supported so that there is a bodily relative movement between it andthe trimming device during the workfeeding movement, and an actuatorcommon to both devices.

13. In a sewing machine, the combination with stitch-forming mechanismfor concatenating an upper and an under thread, of work-holding meansfor holding the work clamped during the stitching operation, means toproduce a relative feeding movement between the stitch-forming mechanismand the work-holding means, a thread-trimming device carried by thework-holding means and operating to cut the under thread beneath thework at the completion of the stitching operation, a pulloff-deviceadapted to pull off a length of under thread from the source of supplyand supported so that there is a bodily relative movement between it andthe trimming device during the work-feeding movement, and an actuatorcommon to both devices, and arranged to actuate'first the pull-offdevice and then to operate the trimming device.

1a. In a sewing machine, the combination with a frame, of work-holdingmeans movably mounted thereon, means to give said work-holding means afeeding movement, stitch-forming mechanism constructed to concatenate anupper and an under thread, a pull-off device mounted on the frame andadapted to pull off a length of under thread from the source of supply,and a thread-trimming device carried by and movable with thework-holding means for cutting the under thread beneath the work at theend of the sewing operation.

15. In a sewing machine of the type constructed to sew a short seam andthen come to rest, the combination with a frame, of work-holding meansmovably mounted thereon, means to give said work-holding means a feedingmovement, stitch-forming means constructed to concatenate an upper andan under thread, a pull-off device mounted on the frame and adapted topull off a length of under thread from the source of supply, athread-trimming device can ried by the work-holding means and adapted tocut the under thread beneath the work, and means common to both devicesto actuate them.

In testimony whereof I have signed my name to this specification.

JOHN KIEVV 1C7.

